In order to consistently catch fish using diver sinking tackle or other types of fishing tackle, it is necessary that the bait or lure be presented at the proper depth, since fish tend to maintain activity at a particular depth or range of depths, while avoiding activity at other depths. If the bait or lure is not presented in close proximity to the fish, is it is unlikely that the fish will respond in the desired manner. The use of simple weights has been found to be undesirable, since the weights are typically consumed when a fish strikes, and are not readily reusable. Accordingly, depth control has been sought using special types of fishing tackle such as diver sinking tackle. While a certain level of improvement has been attained, other problems have emerged, especially when several fishermen are working in the same area, as when several trolling lines are operated from the same boat.
The need has arisen for three-dimensioned positioning control, not only to control depth of presentation of the bait or lure, but also for lateral or horizontal positioning control that is needed to avoid interference between the lines of fishermen operating in close proximity to one another. Such interference can lead to tangling of the lines, resulting in downtime and possible loss of fishing equipment. In order to meet the need for greater three-dimensional control, certain improvements have been made over the years to fishing tackle of the diver sinking type. Examples of improvements to such fishing tackle are given in U.S. Pat. No. 2,924,907; No. 3,844,059; No. 3,940,872; and No. 3,643,370.
In U.S. Pat. No. 3,844,059 and No. 3,940,872, for example mechanical fasteners are used to provide operating adjustments to the fishing tackle. One or more threaded fasteners are provided. These fasteners are alternately and arbitrarily tightened and loosened with the aid of a screwdriver or other implement, to allow a weight to be shifted about the flat plate so as to provide a desired lateral repositioning of the path of travel of the fishing device. Unfortunately, tightening and loosening of the fasteners is not controlled, leading to inconsistent operation of the diver sinker device. Other difficulties are encountered, since tools are required for fastener adjustments. A fisherman may find it difficult to manipulate tools to make the needed adjustments when operating from a moving boat or when otherwise off-balance, and particularly after prolonged exposure to cold or inclement weather. Accordingly, improvements in fishing tackle are still being sought.